IDUS对胆胰管疾病的应用体会精选文档精选文档.ppt

Intra-ductal Ultrasonography,IDUS,Advantages of IDUS,With a finer probe,can get approach to the target site through working channel of the endoscopyGet clearer images without the interference of air and fatProbe with higher frequency is enabled with a close distanceImages of high resolution,IDUS vs.routine EUS,The tubular structure of pancreato-billiary duct facilitate the acoustical couplingFluid in duct can be used as medium of ultrasoundThe diameter of the duct is slightly larger than thant of the probeHigher frequency(12-30MHz)Better image resolution,Type of probe,Electronic circular scanSynchronized double section scanMechanical radial scan,Images of normal billiary duct,2-3 layersThickness:0.31-0.79mmSmooth layer with homogenous echoFirst layer:hyper-echogenicity,represents the interphaseSecond layer:hypo-echogenicity,represents mucosal and muscularis propria layersOuter layer:hyper-echogenicity,the echo of fat and interface between serosa and other organs,Clinical application,Suspected stone in CBD,CBD stones,N=35（with suspected stones）Of 21 patients with stones not detected by ERCP,IDUS identified 8,in which 7 were proved by ESTOf 5 patients with suspected stones under ERCP,IDUS identified them as bubblesIDUS changed the clinical strategies in 13(37%)patients,Catanzaro,A,Pfau,P,Isenberg,GA,Wong,RC.Clinical utility of intraductal US for evaluation of choledocholithiasis.Gastrointest Endosc 2003;57:648.,N=62Detect rate of cholangiography:87%IDUS combined with cholangiography:97%,IDUS in cholangiocarcinoma and differentiation between benign and malignant stricture,Features of cholangiocarcinoma under IDUS,Mass of hypo-echo,infiltrating the surrounding tissueHeterogeneous echo inside the massSerrated or irregular marginSurface of papillary protrusionDestruction of normal bile ductSuspected lymphadenectasis,Cholangiocarcinoma,StagingDetection of early lesionsIdentify the margin along the ductDetermine the infiltration of pancreasDetermine the infiltration of portal veinDetermine the infiltration of right hepatic artery,Cholangiocarcinoma,N=?,local staging,compared with pT stagingAccuracy of EUS:54%Accuracy of IDUS:77%IDUS was especially useful for tumors in middle section of CBD and portal fissureWith poor penetration,unable to make M and N stagingUnable to perform FNA,Menzel,J,Domschke,W.Intraductal ultrasonography(IDUS)of the pancreato-biliary duct system.Personal experience and review of literature.Eur J Ultrasound 1999;10:105.,Tamada,K,Kanai,N,Tomiyama,T,et al.Prediction of the histologic type of bile duct cancer by using intraductal ultrasonography.Abdom Imaging 1999;24:484.,Features of malignant stricture,Mass of hypo-echo,Heterogeneous echo,Irregular margin,Papillary protrusion,Destruction of bile duct,Enlarged LN,Stricture of bile duct,IDUSSensibility:89%Specificity:50%Accuracy:76%,Biopsy via percutaneous cholangioscopySensibility:93%Specificity:100%Accuracy:95%,